Writing in 1830, Mr. Parke describes the custom of encoring performers as a prerogative that had been exercised by the public for more than a century; and says, with some justice, that it originated more from self-love in the audience than from gratitude to those who had afforded them pleasure.  He considered, however, that encoring had done service upon the whole, by exciting emulation, and stimulating singers to extraordinary exertion; and that though, in many instances, it destroyed the illusion of the scene, it had become so fixed that, in spite even of the burlesque of encoring Lord Grizzle’s dying song in Fielding’s “Tom Thumb,” it continued to prevail as much as ever.  He notes it as curious that, “in calling for a repetition, the audiences of the French and English theatres should each have selected a word forming no part of their respective languages—­the former making use of the Latin word, bis; and the latter the French word, encore.”  Double encores, we gather from the same authority, first occurred in England, at the Opera House, during the season of 1808, when Madame Catalani was compelled to sing three times one of her songs in the comic opera, “La Freschetana.”  As none of the great singers, her predecessors—­Mara, Banti, Grassini, and Billington—­had ever received a similar compliment, this appeared extraordinary, until the fact oozed out that Catalani, as part of her engagement, had stipulated for the privilege of sending into the house fifty orders on each night of her performance.  After this discovery double encores ceased for a time at the King’s Theatre; but the system reappeared at Covent Garden, by way of compliment to Braham, each time the great tenor sang the favourite polacca in the opera of “The Cabinet;” and subsequently like honours were paid to Sinclair upon his return from Italy.  Until then, it would seem, Mr. Sinclair had been well satisfied with one encore, and exceedingly anxious that smaller favour should, on no account, be withheld from him.  When he played the part of Don Carlos, in the opera of “The Duenna,” he was disappointed with the measure of applause bestowed upon his efforts, and complained that the obbligato cadenza—­which Mr. Parke had time out of mind played on the oboe in the symphony of the song, “Had I a heart for falsehood framed”—­interfered with the effect of his singing, and that the applause which was obtained by the cadenza deprived him of his encore.  Accordingly he requested that the cadenza might be suppressed.  “Though I thought this a mean and silly application,” says Mr. Parke, “I complied with it, and never interfered with his encores afterwards.”  It must be said for Sinclair, however, that encores had come to be regarded as tests of a singer’s merits, and that a re-engagement at the theatre sometimes depended upon this demonstration of public approval.  At Vauxhall Gardens, indeed, the manager—­“who was not,” says Mr. Parke, “a musical luminary”—­formed his opinion of the capacities of his singers from